feat (server): new method to check regex regions of a text

Author: mdevolde

coverage-badge.svg

@@ -6,6 +6,7 @@
 import json
 import logging
 import random
+import re
 import socket
 import subprocess
 import time
@@ -610,6 +611,41 @@ def check(self, text: str) -> List[Match]:
         matches = response["matches"]
         return [Match(match, text) for match in matches]
 
+    def check_matching_regions(
+        self, text: str, pattern: str, flags: int = 0
+    ) -> List[Match]:
+        """
+        Check only the parts of the text that match a regex pattern.
+        The returned Match objects can be applied to the original text with
+        :func:`language_tool_python.utils.correct`.
+
+        :param text: The full text.
+        :param pattern: Regular expression defining the regions to check
+        :param flags: Regex flags (re.IGNORECASE, re.MULTILINE, etc.)
+        :return: List of Match with offsets adjusted to the original text
+        :rtype: List[Match]
+        """
+
+        # Find all matching regions
+        matches_iter = re.finditer(pattern, text, flags)
+        regions = [(m.start(), m.group()) for m in matches_iter]
+
+        if not regions:
+            return []  # No regions to check
+
+        all_matches: List[Match] = []
+
+        for start_offset, region_text in regions:
+            region_matches = self.check(region_text)
+
+            # Adjust offsets for the original text
+            for match in region_matches:
+                match.offset += start_offset
+
+            all_matches.extend(region_matches)
+
+        return sorted(all_matches, key=lambda m: m.offset)
+
     def _create_params(self, text: str) -> Dict[str, str]:
         """
         Create a dictionary of parameters for the language tool server request.

language_tool_python/server.py

@@ -182,3 +182,26 @@ def test_special_char_in_text() -> None:
             tool.correct(text)
             == "The sun was setting 🌅, casting a warm glow over the park. Birds chipped softly 🐦 as the day slowly fade into night."
         )
+
+
+def test_check_with_regex() -> None:
+    """
+    Test the check_matching_regions method for selective grammar checking.
+    This test verifies that LanguageTool can limit its grammar checking to specific
+    regions of text defined by a regular expression, allowing for targeted error detection.
+    Additionally, the test is performed with some special characters in the text to ensure
+    correct handling of offsets.
+
+    :raises AssertionError: If the detected matches do not correspond to the specified regions.
+    """
+    import language_tool_python
+
+    with language_tool_python.LanguageTool("en-US") as tool:
+        text = '❗ He said "❗ I has a problem" but she replied ❗ "It are fine ❗".'
+        matches = tool.check_matching_regions(text, r'"[^"]*"')
+
+        assert len(matches) == 2
+        assert (
+            language_tool_python.utils.correct(text, matches)
+            == '❗ He said "❗ I have a problem" but she replied ❗ "It is fine ❗".'
+        )